Sunday, February 1, 2015

Osteospermums in the Garden, and Don't Always Believe What They Tell You

Osteospermum Avalanche

Osteospermum hybrid

Osteospermum hybrid

Osteospermum hybrid

Osteospermum hybrid

In the front, along a the walkway I put in a slightly raised area with lots of road sand and planted it full of delospermas and five different kinds of osteospermums, among a few other things. Four of the osteospermums were from Home Depot, who knows what they are, but they all bloomed nicely all season long. I also brought 3 plants of O. "Avalanche" from High Country Gardens, they grow differently, making a mat of foliage with white daisies rising on single stems above the foliage. One of the three plants was more vigorous than the other two, but all bloomed off and on all season. I never got quite the show they get in Denver with them but I was pleased and they are supposed to be winter hardy. Before the recent snows came, they certainly seemed fine, while of course the Home Depot hybrids were long dead from frost.

I made a point of finding and collecting good seed from all of them, and found plenty of what appears to be good seed on the Home Depot hybrids. Avalanche is supposed to be sterile, but with careful attention I found a few sound looking seeds on it too. Not many, and now that I planted them most turned out to be empty shells but I am happy to report I have two nice seedlings coming along. I don't know if they crossed with the HD hybrids or if they are selfed, though I suspect the latter. It will be interesting to see how they compare to the parent plants later on this year.

Osteospermums produce two kinds of seeds, flattened ones in the middle and triangular, much thicker, ones on the outer ring of the center of the flower. In the case of Avalanche, the few good seeds were all triangular, in the Home Depot hybrids they tended to be triangular with possibly a few good flattened ones. I haven't yet started the HD hybrids but it will be interesting to see how well they germinate and what new colors I might get.

It is possible that Avalanche is mostly sterile not because it is an interspecific cross but because many Asteraceae are self incompatible and all stock of this variety is cutting raised. Sometimes even with self incompatible Asteraceae one gets a good seed or two anyway.

I'm looking forward to growing more of these South African daisies in my gardens this year, they flower all summer long till frost and seem to not attract critters of the four legged kinds.

5 comments:

Avalanche has an incredibly hardy constitution: if you produce hybrids with the Home Depot stuff you may have something EXTREMELY marketable: I hope you will give P.S. the first crack! Bravo on your efforts. You're a champion.

If I do get a hybrid then I will definitely contact you to get in touch with Plant Select, but I am guessing I have selfs for now. The two seedlings are starting out nicely, but it will be a while before I see if they show the plant habit of Avalanche or the more bushy upright habit of the HD hybrids. Have you ever seen any good seeds on Avalanche or noticed any self seeding? I admittedly watched it very closely and searched each dried inflorescence for seed all summer.

I've not noticed seed on Avalanche, you're right. But then I'd never gotten seed on D. nubigenum 'Lesotho' either--you're the meister in that arena! I had a prolifically seeding strain of barberiae/jucundum that came in every shade of white to deep rose...which I think I fumbled (one time I had dozens of huge clumps). The perils of gardening for too long.

I am not sure about osteospermum hardiness in your country but I have had a large healthy clump of Osteospermum barbariae for fifteen years now in Barnsley in the North of EnglandI sometimes grow the odd garden centre osteospermum in tubs for summer display and they sometimes prove to be winter hardy overwintered in my unheated greenhouse - but never outside. This year they have survived and prolifically self seeded on top of their pot. I will grow some seedlings on this year and see what I get!

About Me

I'm a high school biology teacher with a passionate interest in plants for as long as I can remember. I have two horticulture degrees, BS and Ph.D. from Cornell and I've worked at the New York Botanical Garden in the past. My plant interests are quite simple: everything! Still, I have a special affection for South African plants, including, of course, pelargoniums (aka "geraniums").